ADDITIONS AND CORRECTIONS. 



Page 109, equation (10). Lord Kelvin maintains that the type of motion here 

 contemplated, with a surface of discontinuity, and a mass of ' dead water ' in the rear 

 of the lamina, has no resemblance to anything which occurs in actual fluids ; and 

 that the only legitimate application of the methods of von Helmholtz and Kirchhoff 

 is to the case of free surfaces, as of a jet. Nature, 1. 1. , pp. 524, 549, 573, 597 (1894). 



Page 111, line 20, for a = read a = 90. 

 132, equation (4), dele u 2 . 



,, 156, equation (3), footnote. The author is informed that this solution 

 was current in Cambridge at a somewhat earlier date, and is due to Dr Ferrers. 



Page 305, footnote. To the list of works here cited must now be added : Gray 

 and Mathews, A Treatise on Bessel Functions and their Applications to Physics, 

 London, 1895. 



Page 376, line 22, for (g\fiir)* read (27T0/X)*. 



381, line 10. Eeference should be made to Scott Russell, Brit. Ass. 

 Rep., 1844, p. 369. 



Page 386, equation (2). Attention has recently been called to some obser- 

 vations of Benjamin Franklin (in a letter dated 1762) on the behaviour of surfaces 

 of separation of oil and water (Complete Works, 2nd ed., London, n. d., t. ii., 

 p. 142). The phenomena depend for their explanation on the fact that the natural 

 periods of oscillation of the surface of separation of two liquids of nearly equal 

 density are very long compared with those of a free surface of similar extent. 



Page 423, line 16, for the minimum condition above given read the con- 

 dition that 5(F-T ) = 0, ord(V+K) = 0. 



Page 449, footnote, for Art. 302 read Art. 303. 



482, line 16, for <f> read 0. 



487, footnote. The solution of the equation (1) of Art. 266 in spherical 

 harmonics dates from Laplace, " Sur la diminution de la duree du jour, par le 

 refroidissement de la Terre," Conn, des Terns pour VAn 1823, p. 245 (1820). 



Page 491. Dele lines 918 and footnote. 



